A computer collects first test metrics on a transaction hosted within a middleware container, and is executing within a first environment. The computer generates baseline values of expected execution behavior of the transaction based on the first test metrics. The computer collects second test metrics on the transaction hosted within the middleware container, and is executing within a second environment. The computer compares the second test metrics to the baseline values. The computer determines whether the second test metrics satisfy the baseline values. In response to the second test metrics not satisfying the baseline values, the computer identifies the transaction as a candidate for cancellation.